1. Field of the Invention
The present invention relates to an apparatus for transfer or dissipation of heat from heat-generating components, and more particularly to a heat spreader having a vapor chamber of a complicated configuration and a method of manufacturing the heat spreader.
2. Description of Related Art
It is well known that heat is generated during operations of a variety of electronic components, such as integrated circuit chips. To ensure normal and safe operations, cooling devices such as heat sinks and/or electric fans are often employed to dissipate the generated heat away from these electronic components.
As progress continues to be made in the electronics art, more components on the same real estate generate more heat. The heat sinks used to cool these chips are accordingly made larger in order to possess a higher heat removal capacity, which causes the heat sinks to have a much larger footprint than the chips. Generally speaking, a heat sink is more effective when there is a uniform heat flux applied over an entire base of the heat sink. When a heat sink with a large base is attached to an integrated circuit chip with a much smaller contact area, there is significant resistance to the flow of heat to the other portions of the heat sink base which are not in direct contact with the chip.
A mechanism for overcoming the resistance to heat flow in a heat sink base is to attach a heat spreader to the heat sink base or directly make the heat sink base as a heat spreader. Typically, the heat spreader includes a vacuum vessel defining therein a vapor chamber, a wick structure provided in the chamber and lining an inside wall of the vessel, and a working fluid contained in the wick structure. As an integrated circuit chip is maintained in thermal contact with the heat spreader, the working fluid contained in the wick structure corresponding to a hot contacting location vaporizes. The vapor then spreads to fill the chamber, and wherever the vapor comes into contact with a cooler surface of the vessel, it releases its latent heat of vaporization and condenses. The condensate returns to the hot contacting location via a capillary force generated by the wick structure. Thereafter, the condensate frequently vaporizes and condenses to form a circulation to thereby remove the heat generated by the chip. In the chamber of the heat spreader, the thermal resistance associated with the vapor spreading is negligible, thus providing an effective means of spreading the heat from a concentrated source to a large heat transfer surface.
Conventionally, the wick structure of the heat spreader is a grooved or sintered type. However, in view of traditional manufacturing processes, it is difficult to manufacture a heat spreader having a complicated configuration since it is difficult to carve tiny grooves or sinter complicated porous structures in an inner surface of a complicated configuration. Thus, the heat spreader can not be used in a complicated system, which causes the heat generated by the chips of the complicated system can not be timely removed. Therefore, it is desirable to provide a method of manufacturing a heat spreader which may have a complicated configuration.